Questions about filing taxes as a sole proprietor

I haven't fully launched my business yet, but I filed my LLC (sole proprietor) at the end of 2023, but haven't made any money yet.  I signed up for QuickBooks® Solopreneur, and it looks like I can just file year-end taxes.

 

  1. Do I still need to make estimated quarterly taxes if I'm a sole proprietor? I read somewhere that sole proprietors can just file year-end taxes.
  2. If so, how do I file quarterly taxes? 
  3. How do I calculate quarterly estimated taxes?
  4. What is the penalty for not paying or filing on time?
  5. If I haven't filed on time, what is the process to file for the time that was not submitted even if I haven't made any money yet since it's a startup?